The revival of the 25C Energy Tax Credit went almost unnoticed in Congress' "fiscal cliff" legislation, H.R. 8, the American Taxpayer Relief Act of 2012. The energy tax credit was extended through the end of 2013 and made RETROACTIVE to products install in 2012! (It had previously expired at the end of 2011). Applied to qualified energy efficiency improvements, the credit is capped at 10 percent of the product cost with a $500 lifetime limit.